Anyone got any ideas on what might be causing a big clunk?

I recently replaced, well, just about everything. I put all new suspension on, plus all new steering components, brakes, ball joints and U joints, etc. So just about everything I've messed with lately and possibly also messed up

I can't replicate the clunk by bouncing on the bumper or from open passenger door, though I can get the truck bouncing it seems to take a harsh hit to trigger the clunk. I can feel it through the body - like a modest whack from a sledge hammer is hitting the frame. It seems to be when the suspension drops, like into a pothole, not so much from hitting a bump - I think but I could be wrong. And it doesn't do it if I hit a pothole with just the driver's tire, only for passenger side front tire. I've looked everything over again, nothing is out of place I can tell, shock securely mounted, sway bar bolted up, etc. The clunk is slightly jarring to the handling, making the potholes feel extra rough. I know its a long shot trying to troubleshoot something like this without being there,but open to any ideas and things to check.

 

From my 30k foot view it sounds like your body mounts could be shot.

 

Certainly possible, with all the rust this truck has. However I figured it was more likely related to the fact I just replaced all the steering and suspension components, never underestimate my ability to screw something up lol. I'll see if I can inspect the body mounts, though its something that I can't say I've ever really looked at before.

 

truck details would be helpful here.
what year is the truck? 4 wheel drive? How old are the shocks?
I think I’d look at body mounts for deterioration first, then lift the front end to unload the suspension to grab and yank to see if you can locate the issue.
good luck.

 

People don't realize you can't see the signatures in posts if you're using a mobile browser. If it's the truck in his sig, it's a 2009, so definitely in the years of the magical, disappearing body mount bushings.

 

I wonder why sigs are not shown on mobile, it's like why I put my vehicle info there so I don't have to keep repeating it in various threads, which I suppose would be especially handy on mobile since extra typing on a small phone screen is a pain.

Anyways, yes its a 2009 F350 4x4. And the shocks are new, everything in the suspension was replaced (except the original radius arms I decided to keep), as well as the steering. There was no clunk a few months ago before I started the suspension work.

 

Yeah, it doesn't make sense anymore. There's no real reason to try to save the bandwidth from a few lines of text when most ppl have unlimited data.

 

My 05 does the same thing. It sounds violent. I'm fairly certain mine is sway bar end link.

 

You guys were dead on... I think, I dunno anything about body mounts but this doesn't look right to me


I assume there is supposed be rubber or something in there. So how big of a job is replacing these?

 

I was pretty confident that’s what it was from what you were describing. Mine actually looked a bit worse than that, but yep those are shot. Overall not the most hateful job, but time consuming. There are some good videos out there including Automedic, Left Lane Diesel, and Atomic Diesel. S&B body mount kits are far superior to the cheap ones. Take your time, try not to use an impact, use a penetrating lube liberally, do one side at a time.Good luck.

 

Heat will be your best friend. They use thread locker on the bolts. It doesn't even need to be a torch; a heat gun will work.

 

Thanks fellas. I'll look up some videos. Heat isn't an issue I do have oxy propane torch setup... Believe me it was needed when I replaced the suspension and steering. Well that and a plasma cutter...

 

Went out in the daylight to better inspect. Yeah the lower bushing totally missing. Other side is half there. Middle cab mounts seem ok, rear most had some pieces left until I touched them, now both totally missing also.

Just watched a bunch of videos. And read the comments. Based on what I'm seeing, I'm guessing I'll have around 100% chance of spinning more than one of these. I don't think locktite is any issue lol most of the bolts I've taken off recently have been corrosion welded together. Even with a torch I've snapped bolts before the nuts loosened a couple times. I'm going to have to plan on this being a major pita. I saw plenty of non-rusted southern trucks even spin the bolts, so mine don't even stand a chance. I might try and get a quote for this job, but I'm probably not going to like it. Or at the least I'll need to allocate plenty of time.

One problem it seems when you spin a nut you need another person to hold it topside. I don't really have anyone I know nearby here, so on my own. And I'm not going to invite someone over from 1hr+ away for the first time just to bust up there knuckles helping me. Maybe if I had friends that did this kind of stuff but I don't. I haven't really tried to look at the top side nuts yet, is it really not able to just wedge a wrench there to hold it and go back below?

 

Where there's a will, there's a way... I do 90% of my work alone; sometimes you just have to get creative.

 

I have replaced more than my share of body mounts on this era of Ford Super Duty trucks. They are very challenging to replace due to the thread locker that is used at the factory. It is loctite on steroids. You need to heat the bolt in order to break the bond. If you spin the nuts in the body at the front of the vehicle, you are SOL. Gaining access to the nut is a VERY challenging and unnecessary task if you use the correct tools. Using a torch is not recommended due to the possibility of starting a fire. I have seen a cab go up in flames when a mechanic caught the interior on fire using a torch on a rear cab mount bolt. I highly recommend investing in a bolt induction heater. Maybe you can rent one. The bolt induction heater will heat the bolt cherry red in very short order without heating the mount or any other part in the vacinity. The first time I used one, I couldn't believe how effective it was. You will save yourself a lot of time and grief if you get one.